Surgical treatment of lung metastases in patients with embryonal pediatric solid tumors: an update

Targeting pediatric solid tumors in the new era of RNA therapeutics

Despite substantial progress in pediatric cancer treatment, poor prognosis remained for patients with recurrent or metastatic disease, given the limitations of approved targeted treatments and immunotherapies. RNA therapeutics offer significant potential for addressing a broad spectrum of diseases, including cancer. Advances in manufacturing and delivery systems are paving the way for the rapid development of therapeutic RNAs for clinical applications. This review summarizes therapeutic RNA classifications and the mechanisms of action, highlighting their potential in manipulating major cancer-related pathways and biological effects. We also focus on the pre-clinical investigation of RNA molecules with efficient delivery systems for their therapeutic potential targeting pediatric solid tumors.

An update on diagnosis and treatment of hepatoblastoma

Hepatoblastoma (HB) remains the most common paediatric liver tumour and survival in children with hepatoblastoma has improved considerably since the advent of sequential surgical regimens of chemotherapy based on platinum-based chemotherapeutic agents in the 1980s. With the advent of modern diagnostic imaging and pathology techniques, new preoperative chemotherapy regimens and the maturation of surgical techniques, new diagnostic and treatment options for patients with hepatoblastoma have emerged and international collaborations are investigating the latest diagnostic approaches, chemotherapy drug combinations and surgical strategies. Diagnosis of hepatoblastoma relies on imaging studies (such as ultrasound, computed tomography, and magnetic resonance imaging), alpha-fetoprotein (AFP) levels, and histological confirmation through biopsy. The standard treatment approach involves a multimodal strategy with neoadjuvant chemotherapy followed by surgical resection. In cases where complete resection is not feasible or tumors exhibit invasive characteristics, liver transplantation is considered. The management of metastatic and recurrent hepatoblastoma poses significant challenges, and ongoing research focuses on developing targeted therapies and exploring the potential of immunotherapy. Further studies are necessary to gain a better understanding of the etiology of hepatoblastoma, develop prevention strategies, and personalize treatment approaches. We aim to review the current status of diagnosis and treatment of hepatoblastoma.

Modelling the impact of liver regeneration on hepatoblastoma patient-derived-xenograft tumor growth

BACKGROUND

Twenty percent of children with hepatoblastoma (HB) have lung metastasis at diagnosis. Treatment protocols recommend surgical removal of chemotherapy-refractory lung nodules, however no chronological order is established. As hepatectomy is followed by release of growth factors, it has been proposed that partial hepatectomy (PH) could boost local or distant residual tumor growth.

METHODS

To evaluate the impact of PH on distant tumor growth, PH was performed in mice subcutaneously implanted with a HB patient-derived xenograft (PDX). The influence of PH on tumor growth at primary site was assessed by performing PH concomitantly to HB PDXs orthotopic implantation.

RESULTS

Subcutaneously implanted HB PDX failed to show any influence of hepatectomy on tumor growth. Instead, intrahepatic tumor growth of one of the 4 HB PDXs implanted orthotopically was clearly enhanced. Cells derived from the hepatectomy-sensitive HB PDX exposed to hepatic growth factor (HGF) showed increased proliferation rate compared to cells derived from a hepatectomy-insensitive model, suggesting that the HGF/MET pathway could be one of the effectors of the crosstalk between liver regeneration and HB growth.

CONCLUSION

These results suggest that hepatectomy can contribute to HB growth in some patients, further studies will be necessary to identify biomarkers predictive of patient risk of PH-induced HB recurrence.

IMPACT

Key message: Cytokines and growth factors secreted following partial hepatectomy can contribute to intrahepatic tumor growth in some hepatoblastoma models. What does it add to the existing literature: It is the first article about the impact of liver regeneration induced by partial hepatectomy on hepatoblastoma local or distant tumoral growth in nude mice. What is the impact: It is important to identify the secreted factors that enhance tumor growth and to define biomarkers predictive of patient risk of partial hepatectomy-induced hepatoblastoma recurrence.

Feasibility of indocyanine green-guided localization of pulmonary nodules in children with solid tumors

BACKGROUND

Clearing all pulmonary metastases is essential for curing pediatric solid tumors. However, intraoperative localization of such pulmonary nodules can be challenging. Therefore, an intraoperative tool that localizes pulmonary metastases is needed to improve diagnostic and therapeutic resections. Indocyanine green (ICG) real-time fluorescence imaging is used for this purpose in adult solid tumors, but its utility in pediatric solid tumors has not been determined.

METHODS

A single-center, open-label, nonrandomized, prospective clinical trial (NCT04084067) was conducted to assess the ability of ICG to localize pulmonary metastases of pediatric solid tumors. Patients with pulmonary lesions who required resection, either for therapeutic or diagnostic intent, were included. Patients received a 15-minute intravenous infusion of ICG (1.5 mg/kg), and pulmonary metastasectomy was performed the following day. A near-infrared spectroscopy iridium system was optimized to detect ICG, and all procedures were photo-documented and recorded.

RESULTS

ICG-guided pulmonary metastasectomies were performed in 12 patients (median age: 10.5 years). A total of 79 nodules were visualized, 13 of which were not detected by preoperative imaging. Histologic examination confirmed the following histologies: hepatoblastoma (n = 3), osteosarcoma (n = 2), and one each of rhabdomyosarcoma, Ewing sarcoma, inflammatory myofibroblastic tumor, atypical cartilaginous tumor, neuroblastoma, adrenocortical carcinoma, and papillary thyroid carcinoma. ICG guidance failed to localize pulmonary metastases in five (42%) patients who had inflammatory myofibroblastic tumor, atypical cartilaginous tumor, neuroblastoma, adrenocortical carcinoma, or papillary thyroid carcinoma.

CONCLUSIONS

ICG-guided identification of pulmonary nodules is not feasible for all pediatric solid tumors. However, it may localize most metastatic hepatic tumors and high-grade sarcomas in children.

Thoracoscopic Resection of Lung Nodules following CT-Guided Labeling in Children and Adolescents with Solid Tumors

Resection of lung metastases in children with solid tumors is regularly hampered by limited intraoperative detectability and relevant operative trauma of the open surgical access. The aim of this study was to analyze thoracoscopic resection of lung metastases in children following CT-guided labeling with coil wires. We retrospectively analyzed data of children and adolescents undergoing this approach at our institution between 2010 and 2022 with regard to technical aspects as well as surgical and oncological data. Within this period, we performed this procedure on 12 patients wherein we resected 18 lesions (1–5 per patient). The median age of patients was 178 months (51–265). The median duration of coil wire placement was 41 min (30–173) and the median surgery time was 53 min (11–157). No conversions were necessary and no intraoperative complications occurred. Complete microscopic resection (R0) was achieved in all labeled lesions and malignant tumor components were found in 5/12 patients. Our study shows that with a careful patient selection, thoracoscopic resection of lung metastases after coil wire labeling is a safe and reproducible procedure in children. Using this approach, lesions that are expected to have a reduced intraoperative detectability during open surgery become resectable. Patients benefit from the minimally invasive surgical access and reduced operative trauma.

Developments in the Surgical Approach to Staging and Resection of Rhabdomyosarcoma

Although survival after rhabdosarcoma treatment has improved over the years, one third of patients still develop locoregional relapse. This review aims to highlight developments pertaining to staging and local treatment of specific RMS tumor sites, including head and neck, chest/trunk, bladder-prostate, female genito-urinary, perianal, and extremity sites.

Interdisciplinary surgical approach enables complete tumor resection with preservation of neurological function in specific conditions of pediatric solid malignancies

PURPOSE

Success of pediatric solid tumor surgery is regularly hampered by infiltration of essential neurovascular structures. A surgical dilemma arises when imaging data suggest a conflict between complete resection and preservation of neurological function. The aim of the study was to analyze data of children harboring tumors with involvement of neurovascular structure treated by an interdisciplinary pediatric surgical/neurosurgical team.

METHODS

We retrospectively analyzed data of 25 children undergoing surgery for solid tumors, in whom preoperative imaging showed a relevant involvement of nerve structures. Surgery was simultaneously performed by a pediatric onco-surgeon and a pediatric neurosurgeon with peripheral nerve expertise, including intraoperative electrophysiological monitoring.

RESULTS

The following tumors were treated: NF1 associated neurofibromas (10), neuroblastomas (5), desmoid tumors (2), MPNST (2), ganglioneuroma (1), Ewing sarcoma (1), infantile fibromatosis (1), PNET (1), rhabdomyosarcoma (1), angiolipoma (1). The most frequent tumor localizations were the pelvis (n = 7) and retroperitoneal region (n = 6). Median age at surgery was 8 years (1.5-16). Macroscopically complete tumor resection was achieved in 24/25 patients. In 2/4 patients with limb tumors an amputation was planned externally. In both, a limb-salvage procedure was possible. Transient postoperative neurological deficits occurred in 2/25 patients. Four patients had tumor relapses. All but one are alive after a median follow-up of 46 months (2-155).

CONCLUSIONS

Simultaneous interdisciplinary pediatric surgical/neurosurgical approach enables radical tumor resection with preservation of neurological function in patients suffering from solid tumors with involvement of relevant neurovascular structures. This approach should be performed by experienced surgeons in reference pediatric onco-surgical centers.

Chirurgische Therapie maligner Lungen- und Brustwandtumoren bei Kindern

Primäre Lungen- und Brustwandtumoren sowie Lungenmetastasen stellen bei Kindern äußerst seltene Erkrankungen dar. Eingebunden in multimodale Therapiekonzepte können thoraxchirurgische Eingriffe bei pädiatrischen onkologischen Erkrankungen dazu beitragen, die Prognose der erkrankten Kinder signifikant zu verbessern. Ziel des Übersichtsartikels ist es, die Indikationsstellung und die aktuellen thoraxchirurgischen Therapieoptionen bei malignen Brustwand- und Lungentumoren darzustellen sowie den aktuellen Stellenwert der pulmonalen Metastasenchirurgie bei Kindern zu beleuchten. Die Arbeit stellt darüber hinaus das Diagnosespektrum und thoraxchirurgische Operationsspektrum im Bereich der onkologischen pädiatrischen Thoraxchirurgie an einem spezialisierten Zentrum in Deutschland dar.

Interhospital variability in localization techniques for small pulmonary nodules in children: A pediatric surgical oncology research collaborative study

BACKGROUND

Pulmonary nodules that are deep within lung parenchyma and/or small in size can be challenging to localize for biopsy. This study describes current trends in performance of image-guided localization techniques for pulmonary nodules in pediatric patients.

METHODS

A retrospective review was performed on patients < 21 years of age undergoing localization of pulmonary nodules at 15 institutions. Localization and resection success, time in interventional radiology (IR), operating room (OR) and total anesthesia time, complications, and technical problems were compared between techniques.

RESULTS

225 patients were included with an average of 1.3 lesions (range 1-5). Median nodule size and depth were 4 mm (range 0-30) and 5.4 mm (0-61), respectively. The most common localization techniques were: wire + methylene blue dye (MBD) (28%), MBD only (25%), wire only (14%), technetium-99 only (11%), coil + MBD (7%) and coil only (5%). Localization technique was associated with institution (p < 0.01); technique and institution were significantly associated with mean IR, OR, and anesthesia time (all p < 0.05). Comparing techniques, there was no difference in successful IR localization (range 92-100%, p = 0.75), successful resection (94-100%, p = 0.98), IR technical problems (p = 0.22), or operative complications (p = 0.16).

CONCLUSIONS

Many IR localization techniques for small pulmonary nodules in children can be successful, but there is wide variability in application by institution and in procedure time.

LEVEL OF EVIDENCE

Retrospective review, Level 3.

The role of liver resection in metastatic nephroblastoma: a systematic review and Meta-regression analysis

BACKGROUND

The impact of hepatic resection for liver metastases (LM) on the survival of pediatric patients with Wilms' tumor (WT) is unclear. So far, there is a lack of studies investigating the best suited treatment for patients with WTLM, and the role of liver resection has rarely been investigated. Thus, the development of evidence-based guidelines concerning indications of liver resection for WTLM remains difficult.

AIM

To investigate the role of surgery in the therapy of WTLM. All available data on liver resections and subgroup outcomes of patients with WTLM are analyzed. Main research question is whether liver resection improves survival rates of patients with WTLM compared to non-surgical treatment.

METHODS

A systematic literature search of MEDLINE, Web of Science, and Central provided the basis for this PRISMA-compliant systematic review. For the main analysis (I), all studies reporting on surgical treatment of pediatric WTLM were included. To provide a representative overview of the general outcome of WTLM patients, in analysis II all studies with cohorts of at least five WTLM patients, regardless of the kind of treatment, were reviewed and analyzed. A Multiple meta-regression model was applied to investigate the impact liver resection on overall survival.

RESULTS

14 studies with reports of liver resection for WTLM were found (Analysis I). They included a total of 212 patients with WTLM, of which 93 underwent a liver resection. Most studies had a high risk of bias, and the quality was heterogenous. For the analysis II, eight studies with subgroups of at least five WTLM patients were found. The weighted mean overall survival (OS) of WTLM patients across the studies was 55% (SD 29). A higher rate of liver resection was a significant predictor of better OS in a multiple meta-regression model with 4 covariates (I2 29.43, coefficient 0.819, p = 0.038).

CONCLUSIONS

This is the first systematic review on WTLM. Given a lack of suited studies that specifically investigated WTLM, ecological bias was high in our analyses. Generating evidence is complicated in rare pediatric conditions and this study must be viewed in this context. Meta-regression analyses suggest that liver resection may improve survival of patients with WTLM compared to non-surgical treatment. Especially patients with persisting disease after neoadjuvant chemotherapy but also patients with metachronous LM seem to benefit from resection. Complete resection of LM is vital to achieve higher OS. Studies that prospectively investigate the impact of surgery on survival compared to non-surgical treatment for WTLM are highly needed to further close the current evidence gap.

STUDY REGISTRATION

PROSPERO 2021 CRD42021249763  https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=249763 .

The role of thoracoscopic lung biopsy in the management of children with solid organ malignancies and suspected lung metastases in a developing country

Background

Accurate diagnosis of lung lesions appearing on computed tomographic (CT) imaging in children with solid organ malignancies can be difficult. Therefore, this study aimed to determine, in a developing country setting, (1) the utility of thoracoscopic lung biopsy for assessment of suspected lung metastases in solid organ malignancies, and (2) the pathology of biopsied lesions suspected to be malignancies. The electronic records of all patients with solid organ malignancies who underwent thoracoscopic lung biopsies for suspected metastases at a tertiary hospital in South Africa between January 2012 and December 2017 were analysed retrospectively.

Results

A total of 29 thoracoscopic biopsies were taken from 25 patients. In eight biopsies (27.6%), viable metastatic tumour was identified; in one, a completely necrotic tumour was found. Seven patients (28.0%) were found to have infective aetiologies which required alternative therapies: of these, three patients had tuberculosis; three had bronchopneumonia and one had a fungal lung infection. Other findings included haemorrhagic infarction (n = 1); non-specific fibrosis (n = 1) and reactive lymph node (n = 1). In ten biopsies (34.5%), no lesion was found on thoracoscopy.

Conclusions

Thoracoscopy was found to improve the management of children with solid organ malignancies and suspected metastases. Thoracoscopy enabled many patients to avoid additional chemotherapy and radiotherapy and its negative consequences and enabled therapy for specific benign pathologies including infections.

A Surgical Approach to Pulmonary Metastasis in Children

Decisions regarding the role of surgery in pulmonary metastasis need to take into account histology and biology of the cancer. Response to chemotherapy and radiotherapy, balanced with toxicities, factors into decisions about metastasectomy. The less sensitive the tumor is to adjuvant therapy, the more likely that metastasectomy may be beneficial. Broad principles include the following: the aims of resection are localized resections with clear margins, with the aim of preserving adequate lung volume; unnecessary toxic therapy sometimes is avoided with accurate diagnosis; tumor type is of utmost importance; and number of metastases and the disease-free interval are not contraindications to metastasectomy.

Pediatric thoracic mass lesions: Beyond the common

Thoracic mass lesions can be categorized as originating in one of the three major compartments: a) chest wall and pleura, b) lung parenchyma and airways, c) mediastinum. While some of these, such as lymphoma, are common in both children and adults, others are rare and unique to childhood. The goal of this review is to familiarize radiologists with unusual but distinctive mass lesions of the pediatric thorax.

Pulmonary Metastasectomy in Pediatric Solid Tumors

Metastatic disease and the complications of treating metastatic disease are the primary causes of mortality in children with solid malignancies. Nearly 25% of children with solid tumors have metastatic disease at initial diagnosis and another 20% develop metastases during or after treatment. The most common location of these metastases is the lung. The role of surgery in metastatic disease depends greatly on the histology of the primary. In general, tumors that are refractory to adjuvant therapies are most appropriate for pulmonary metastasectomy. This article will summarize the indications for metastasectomy in pediatric solid tumors and discuss the ongoing debate over the technique of metastasectomy in osteosarcoma.

Use of radiotracer labeling of pulmonary nodules to facilitate excisional biopsy and metastasectomy in children with solid tumors

PURPOSE

Excision of suspected pulmonary metastases in children is challenging in the setting of multiple nodules or nodules that are small, deep, or soft. This study describes preoperative technetium macro-aggregated albumin (Tc 99m MAA) localization of pulmonary lesions to aid in intraoperative identification and resection.

METHODS

Patients with past or present pediatric solid tumors who underwent resection of pulmonary nodules following CT-guided Tc 99m MAA labeling were identified. The primary outcomes were successful preoperative localization and subsequent resection.

RESULTS

Metastasectomy following Tc 99m MAA localization was performed 15 times in 11 patients from 2014 to 2016. Mean age was 13years; the most common diagnosis was osteosarcoma (33%). Tc 99m MAA labeling was attempted in 24 nodules with mean nodule diameter 6±5mm and mean depth from the pleural surface of 12±17mm; localization was successful in 23 nodules (96%). Subsequent resection was performed by thoracotomy in 12 cases and thoracoscopy in 3. All labeled nodules were identified intraoperatively; two were not resected and 17 of the 21 nodules resected demonstrated metastatic disease on pathology.

CONCLUSION

Tc 99m MAA labeling of pulmonary nodules in children is effective in facilitating resection of sub-centimeter intraparenchymal metastases identified on preoperative imaging. Furthermore, this technique allows for thoracoscopic metastasectomy in select patients.

TYPE OF STUDY/LEVEL OF EVIDENCE

Case Series/Level IV.

The role of pulmonary metastasectomy for hepatoblastoma in children with metastasis at diagnosis: Results from the JPLT-2 study

BACKGROUND/PURPOSE

The purpose of this study was to clarify the role of pulmonary metastasectomy in hepatoblastomas with lung metastasis at diagnosis. We reviewed cases enrolled in the JPLT-2 study.

METHODS

A total of 360 cases with hepatoblastoma were enrolled. The clinical courses and outcome of 60 cases with pulmonary metastasis at diagnosis were reviewed, focusing on metastasectomy.

RESULTS

Induction chemotherapy resulted in eradication of nodules in 26, residual nodules in 33, and early treatment-related death in one. Of the 33 cases with residual nodules, 11 underwent complete resection of the lung lesions, and among these, progression was reported in five. Complete resection of the liver tumor was not achieved in two of these. Three underwent incomplete resection of lung nodules, eventually leading to progression. Twelve cases with incomplete or no liver tumor resection progressed regardless of the status of lung lesions. Contrarily, among patients who underwent complete resection of the liver tumor, half were cured without metastasectomy.

CONCLUSIONS

Metastasectomy for residual pulmonary nodules after induction chemotherapy is effective provided that the liver tumor could be completely resected.

TYPE OF STUDY

Prospective Cohort Study.

LEVEL OF EVIDENCE

Level II.

The effect of immune checkpoint inhibitors on lung metastases of osteosarcoma

BACKGROUND/PURPOSE

The prognosis of patients with metastases remains unsatisfactory in certain pediatric solid tumors. In this study, we evaluated the efficacy of immune checkpoint inhibitors against such metastases using a murine model of osteosarcoma.

METHODS

Murine osteosarcoma LM8 cells were transplanted subcutaneously into C3H mice. The primary tumor lesion was surgically resected 11 days after transplantation. Two hundred micrograms of three antibodies (anti-PD-1, anti-PD-L1, and anti-OX-86) or an isotype antibody were administered intraperitoneally on post-transplantation days 11, 14, 18, and 21. Survival curves were plotted by the Kaplan-Meier method and compared with the log-rank test. Computed tomography (CT) scans were performed on day 11 after tumor transplantation (pre-therapy) and on day 25 (post-therapy). For pathology, 3 mice from each group were euthanized on days 11, 22, and 33 after tumor transplantation.

RESULTS

The antibody-treated group had a significantly longer survival time compared with the control group (p = 0.002). Both the CT scan and pathological results revealed suppression of metastatic tumor proliferation in the treatment group as compared with the control group.

CONCLUSIONS

These results suggest that immune checkpoint inhibitors may be an innovative therapy for lung metastases of advanced pediatric solid tumors.

Phase I study of glypican-3-derived peptide vaccine therapy for patients with refractory pediatric solid tumors

The carcinoembryonic antigen glypican-3 (GPC3) is a good target of anticancer immunotherapy against pediatric solid tumors expressing GPC3. In this non-randomized, open-label, phase I clinical trial, we analyzed the safety and efficacy of GPC3-peptide vaccination in patients with pediatric solid tumors. Eighteen patients with pediatric solid tumors expressing GPC3 underwent GPC3-peptide vaccination (intradermal injections every 2 weeks), with the primary endpoint being the safety of GPC3-peptide vaccination and the secondary endpoints being immune response, as measured by interferon (IFN)-γ enzyme-linked immunospot assay and Dextramer staining, and the clinical outcomes of tumor response, progression free survival (PFS), and overall survival (OS). Our findings indicated that GPC3 vaccination was well tolerated. We observed disease-control rates [complete response (CR)+partial response+stable disease] of 66.7% after 2 months, and although patients in the progression group unable to induce GPC3-peptide-specific cytotoxic T lymphocytes (CTLs) received poor prognoses, patients in the partial-remission and remission groups or those with hepatoblastoma received good prognoses. The GPC3-peptide vaccine induced a GPC3-specific CTL response in seven patients, with PFS and OS significantly longer in patients with high GPC3-specific CTL frequencies than in those with low frequencies. Furthermore, we established GPC3-peptide-specific CTL clones from a resected-recurrent tumor from one patient, with these cells exhibiting GPC3-peptide-specific cytokine secretion. The results of this trial demonstrated that the GPC3-peptide-specific CTLs induced by the GPC3-peptide vaccine infiltrated tumor tissue, and use of the GPC3-peptide vaccine might prevent the recurrence of pediatric solid tumors, especially hepatoblastomas, after a second CR.

Characterization of Pulmonary Metastases in Children With Hepatoblastoma Treated on Children's Oncology Group Protocol AHEP0731 (The Treatment of Children With All Stages of Hepatoblastoma): A Report From the Children's Oncology Group

Purpose To determine whether the pattern of lung nodules in children with metastatic hepatoblastoma (HB) correlates with outcome. Methods Thirty-two patients with metastatic HB were enrolled on Children's Oncology Group Protocol AHEP0731 and treated with vincristine and irinotecan (VI). Responders to VI received two additional cycles of VI intermixed with six cycles of cisplatin/fluorouracil/vincristine/doxorubicin (C5VD), and nonresponders received six cycles of C5VD alone. Patients were imaged after every two cycles and at the conclusion of therapy. All computed tomography scans and pathology reports were centrally reviewed, and information was collected regarding lung nodule number, size, laterality, timing of resolution, and pulmonary surgery. Results Among the 29 evaluable patients, only 31% met Response Evaluation Criteria in Solid Tumors (RECIST) for measurable metastatic disease. The presence of measurable disease by RECIST, the sum of nodule diameters greater than or equal to the cumulative cohort median size, bilateral disease, and ≥ 10 nodules were each associated with an increased risk for an event-free survival event ( P = .48, P = .08, P = .065, P = .03, respectively), with nodule number meeting statistical significance. Ten patients underwent pulmonary resection/metastasectomy at various time points, the benefit of which could not be determined because of small patient numbers. Conclusion Children with metastatic HB have a poor prognosis. Overall tumor burden may be an important prognostic factor for these patients. Lesions that fail to meet RECIST size criteria (ie, those < 10 mm) at diagnosis may contain viable tumor, whereas residual lesions at the end of therapy may constitute eradicated tumor/scar tissue. Patients may benefit from risk stratification on the basis of the burden of lung metastatic disease at diagnosis.

Pediatric oncologic endosurgery

Despite increasing popularity of minimal-invasive techniques in the pediatric population, their use in diagnosis and management of pediatric malignancy is still debated. Moreover, there is limited evidence to clarify this controversy due to low incidence of each individual type of pediatric tumor, huge diversity of the disease entity, heterogeneity of surgical technique, and lack of well-designed studies on pediatric oncologic minimal-invasive surgery. However, a rapid development of medical instruments and technologies accelerated the current trend toward less invasive surgery, including oncologic endosurgery. The aim of this article is to review current literatures about the application of the minimal-invasive approach for pediatric tumors and to give an overview of the current status, indications, individual techniques, and future perspectives.

Pulmonary Nodule Size <5 mm Still Warrants Investigation in Patients With Osteosarcoma and Ewing Sarcoma

BACKGROUND

Osteosarcoma (OS) and Ewing sarcoma (ES) have a high propensity to develop pulmonary metastases. Lung lesions with calcification, peripheral location, and size >5 mm are more likely to represent malignant metastases. We evaluated the incidence of malignancy in nodules 5 mm or less to potentially guide decisions between biopsy and observation.

MATERIALS AND METHODS

A retrospective review of patients <25 years of age with metastatic OS and ES treated at our institution between 2001 and 2014 who had undergone pulmonary nodule biopsy was performed. Computed tomographic scans were reviewed to evaluate nodule size and change over time.

RESULTS

Thirty-five patients (27 OS, 8 ES) met inclusion criteria. One hundred sixteen nodules were biopsied (97 OS, 19 ES). Nodule size at biopsy was not significantly different between the malignant (median, 6 mm, range, 1 to 79 mm) and benign (median, 3 mm, range, 1 to 21 mm) lesions (P=0.063). Size of pulmonary nodules <5 mm was not entirely predictive of benign status, with sensitivity estimate of 0.709 (95% confidence interval, 0.465-0.872; P=0.091) and specificity estimate of 0.776 (95% confidence interval, 0.324-0.962; P=0.219) for all nodules biopsied.

CONCLUSIONS

Pulmonary nodules in patients with OS and ES <5 mm cannot be excluded from biopsy considerations.

Surgical treatment of pulmonary metastases in pediatric solid tumors

Most children who succumb to solid malignancies do so because of the burden of metastatic disease or due to complications associated with the therapy administered to treat metastatic disease. Approximately one-quarter of children with solid tumors will present with metastatic disease, and an additional 20% ultimately develop metastatic disease, most commonly in the lung. The role of surgery in the treatment of metastatic solid tumors, given its disseminated nature, is not intuitive, yet there are circumstances in which surgical resection of metastatic disease can potentially be curative. However, the utility of surgery is very much dependent on histology, and generally is most appropriate for those malignancies with histologies that are refractory to other adjuvant therapies.

Relapsed hepatoblastoma confined to the lung is effectively treated with pulmonary metastasectomy

BACKGROUND

In children diagnosed with hepatoblastoma (HB), the lungs are the most common site of metastasis at both initial presentation and relapse. Previous studies have encouraged pulmonary metastasectomy to achieve a disease-free state after resection of the primary hepatic lesion. However, there is no consensus about how to manage recurrent pulmonary metastasis.

PROCEDURE

A retrospective, multi-institutional review was performed from 2005 to 2014 to identify HB patients ≤18years of age who had disease recurrence associated with pulmonary metastases alone.

RESULTS

Ten patients between the ages of 8 and 33months were identified. Pulmonary metastatic recurrence was detected by measuring alpha-fetoprotein (AFP) levels and/or with CT scans of the chest. All patients subsequently underwent pulmonary metastasectomy without post-operative complications. At last follow-up, 8 patients were alive and had normal AFP levels. The 8 survivors had a median follow-up from therapy completion of 18.5months. Two patients who presented with extrapulmonary recurrence subsequently died of treatment refractory disease.

CONCLUSIONS

This review supports surgical resection as a safe and, in the context of multimodal therapy, efficacious approach to manage HB patients who present with isolated pulmonary relapse.

[Surgical concepts in the treatment of Wilms tumor: An update]

BACKGROUND

Treatment results of Wilms tumors have been impressively improved over the past 50 years resulting in a stage-independent overall survival of greater than 90%. However, unsatisfying treatment results still remain in children with high-risk tumors and tumor relapses.

MATERIALS AND METHODS

This review highlights the current concepts of Wilms tumor surgery as a cornerstone of the treatment strategy for this malignancy. A selective literature review focusing on the past 5 years served as the basis for this article.

RESULTS

Nephron-sparing surgery is associated with an analogue outcome compared to tumor nephrectomy in unilateral Wilms tumors. The surgical panel of the International Society of Pediatric Oncology (SIOP) group has recently introduced a novel nomenclature for organ-preserving resection procedures in order to facilitate a prospective comparison of data. The minimally invasive approach represents an alternative technique with adequate outcome. In bilateral disease, nephron-sparing procedures are gold standard. Complete resection of lung and liver metastases has a significant impact on patients' survival.

CONCLUSIONS

Surgical guidelines for nephron-sparing surgery and minimally invasive tumor nephrectomy need to be established and implemented within newly formulated treatment protocols of the different national and international treatment trials. Risk stratification of patients needs to be more individualized with the aim of reducing late effects while at least maintaining the same survival rates. The unsatisfying treatment results of tumor relapses-associated with low patient numbers within the different trials-emphasize the need for international collaboration.

Experiences and challenges of thorcoscopic lung surgery in the pediatric age group

BACKGROUND

We report a single-center study of minimally invasive thoracoscopic lung surgery with pediatric patients.

METHODS

We performed a retrospective analysis of patients who underwent thoracoscopic lung surgery between 2004 and 2013. The procedures were divided into anatomic and non-anatomical lung resections.

RESULTS

Seventy-six patients with a mean age of 6.5 years (range: 7 days-17 years) and a mean weight of 11 kg (range: 2.6-56.0 kg) received thoracoscopic lung surgery for tumor metastases (n = 20), sequestration/congenital adenomatoid malformation (19), cysts (12), aspergillomas (7), bullae (5), middle lobe syndrome (3), bronchiectasis (3), emphysema (2), and other reasons (5). Twenty-nine anatomical lung resections (Group I: lobectomies, segmentectomies) and 47 non-anatomical lung resections (Group II: wedge resections, lung tissue-sparing surgery) were performed. In 6 cases, preoperative CT-guided coiling was used to localize the lung lesions. Specimen removal was achieved using a widened (2 cm) trocar site. The operating times of Group I patients were longer compared than those of Group II patients (means: 154 and 68 min, respectively); conversion rates (8 versus 2), chest tube insertion rates (100% versus 51%), and postoperative ventilation (48% versus 13%) also differed.

CONCLUSION

Thoracoscopic anatomical lung resections appear to be safe and effective in infants and children. In congenital lung diseases, the key to success is the intraoperative destruction of space-occupying lesions. Limitations exist in cases with infectious adhesions. Non-anatomical lung resections are technically easier and should remain standard in pediatric surgery. Limitations exist in cases of metastases, which are deep within the parenchyma and are not visible on the lung surface.

The role of minimally invasive surgery in pediatric solid tumors

During recent years, minimally invasive surgery (MIS) has become the standard approach for various operations in infants and children. MIS in pediatric thoracic and abdominal tumors is a controversial approach in the surgical management of childhood cancer. Meanwhile, more and more oncological biopsies and resections are being performed laparoscopically or thoracoscopically. Despite its increasing role in pediatric tumor surgery, the different national and international multicenter trial groups have not yet implemented MIS within guidelines and recommendations in most of the current treatment protocols. An increasing number of retrospective reports describes a potential role of MIS in the management of different pediatric oncological entities. Over the time, there has been a diverse development of this approach with regard to the different neoplasms. Nevertheless, there is a lack of prospective randomized trails assessing MIS. This still represents a requirement for evidence-based medicine and judging the advantages and disadvantages of this approach. The purpose of this state-of-the-art article is to review the current literature to describe the application of MIS in pediatric solid tumors.

Local control of metastatic sarcoma

PURPOSE OF REVIEW

Survival rates for children with metastatic sarcoma have remained dismal despite intensified multiagent chemotherapy protocols. The local treatment of metastatic disease has been promoted as a way to eliminate colonies of genetically unstable, heterogeneous metastatic cells in an attempt to improve survival amongst this most unfortunate patient population.

RECENT FINDINGS

The survival benefit offered by pulmonary metastasectomies in patients with metastatic osteosarcoma is well substantiated. Utilization of other local treatment modalities, such as radiation therapy and percutaneous thermal ablation, offers the opportunity to intervene in a wide range of pulmonary and extrapulmonary metastatic disease. Patients who have the entirety of their identifiable disease addressed by local control modalities consistently demonstrate improved survival compared with patients who are treated with systemic therapy in isolation.

SUMMARY

The current state of the literature prevents a definitive conclusion about the utility of local control for metastatic sarcoma. The retrospective trials are clouded by selection bias and the prospective studies are designed to address alternative questions. However, the techniques utilized for local control impart minimal risk to the patient and, in amenable cases, have been shown to provide an opportunity to effect a cure in children with an otherwise dismal prognosis.

Bilateral anterior sternothoracotomy (clamshell incision): a suitable alternative for bilateral lung sarcoma metastasis in children

Background

The aim of our study was to assess the postoperative course of bilateral anterior sternothoracotomy (BAT) in children with sarcoma metastases, in a curative care perspective.

Methods

We reviewed the records of seven patients younger than 18 years old, who underwent surgical procedures for sarcoma metastasis to the lung between 2000 and 2012. We compared the postoperative course of the BAT group with that of patients who underwent unilateral posterolateral thoracotomies (PLTs) for the same etiology.

Results

Of 17 surgical procedures, there were seven BAT and 10 unilateral PLT. Mean ages at the time of the procedures were 12.9 ± 5.4 years old for BAT, and 17.4 ± 1.9 years old for PLT. Mean operative time was 173 ± 37 minutes in the BAT group, and 145 ± 39 minutes in the PLT group (P = 0.19). Patients received epidural analgesia in all cases; this was for a mean time of 3.8 ± 1.3 days in the BAT group, and 3.21 ± 4 days in the PLT group (P = 0.36). Chest tubes were removed after 3.6 ± 1.3 days in the BAT group, and 3 ± 1.2 days in the PLT group (P = 0.69). Total hospital stay was 7.7 ± 6.6 days in the BAT group, and 7 ± 1.2 days in the PLT group (P = 0.72).

Conclusion

In our experience, BAT seems suitable and shows outcomes similar to those of PLT for sarcoma metastasis resection. The BAT procedure allows the manual exploration of both lungs during a single surgical intervention, and so reduces the delay of further therapies.

Minimally invasive surgery for pediatric tumors - current state of the art

During recent years, minimally invasive surgery (MIS) has become the standard approach for various operations in infants and children. This also holds true for surgery in children with solid tumors. Meanwhile, more and more oncological biopsies and resections are being performed laparoscopically or thoracoscopically. Despite its increasing role in pediatric tumor surgery, the different national and international multicenter trial groups have not yet implemented MIS within guidelines and recommendations in most of the current treatment protocols. An increasing number of reports describe a potential role of MIS in the different entities of pediatric surgical oncology. Over the time, there has been a diverse development of this approach with regard to the different neoplasms. The aim of this article is to give an overview and to describe the current state of the art of MIS in pediatric solid tumors.

Outcomes of pulmonary metastases in hepatoblastoma--is the prognosis always poor?

BACKGROUND

Hepatoblastoma is a rare tumour accounting for approximately 1% of all paediatric malignancies. Hepatoblastoma complicated by pulmonary metastatic disease continues to cause management difficulties due to a lack of robust evidence and treatment guidelines.

METHOD

This series is the experience of a tertiary paediatric referral centre. Patients were prospectively enlisted, and their charts were retrospectively reviewed.

RESULTS

Thirty-seven patients were treated for hepatoblastoma from 1995 to 2012 inclusive. The overall survival was 34/37(91.9%). Eight patients had lung metastases at diagnosis (LMD) and twenty-nine did not (NLMD). Two-year EFS was 62.5% in the LMD group and 89.3% in the NLMD group (p=0.078). Overall survival in the LMD and NLMD groups was 100% and 89.7%, respectively (p=0.389). Two patients in the LMD group required multiple thoracic resections to achieve cure. Within the NLMD group, two patients developed lung metastases whilst on treatment, and both of these patients died.

CONCLUSION

In this series, children presenting with lung metastases had a higher risk of relapse but excellent overall survival. However, children who developed pulmonary disease during treatment had a poor prognosis. We advocate aggressive surgical treatment of pulmonary hepatoblastoma to achieve cure.

Surgery for metastatic disease

PURPOSE OF REVIEW

Outcomes for children with cancer have steadily improved and the long-term survival for most early-stage childhood malignancies is now greater than 90%. On the contrary, the prognosis for children with metastatic cancer, though significantly improved from a generation ago, is generally still very disappointing. Surgery continues to play a role in the increasingly aggressive treatment of children with metastatic disease with the ultimate goal of prolonging survival and improving quality of life.

RECENT FINDINGS

Most childhood tumors are relatively rare and are therefore studied using a multi-institutional cooperative group model that standardizes protocols and pools resources and data, accounting for the remarkable progress that has been made in the care of children with cancer. In some cases, this has also allowed us to recognize the utility of certain surgical therapies and the need to further study others.

SUMMARY

Modern surgery and critical care allow us to consider offering children with metastatic disease more aggressive surgical options in circumstances where the data suggest the potential for long-term survival. In situations where data are lacking, children might be offered a surgical option as part of an ongoing trial.

What predicts the risk of recurrent lung metastases?

PURPOSE

The purpose of this study was to determine what factors predict recurrent lung metastatic disease in pediatric oncology patients.

METHODS

A retrospective review of 50 patients who underwent resection of lung nodules that were positive for metastatic disease from 1998 to 2011 was performed. Risk factors for recurrence were determined by multi-variable logistic regression models.

RESULTS

Fifty pediatric oncology patients underwent resection of discrete lung nodules seen on CT scans during work-up for metastasis or for routine surveillance. Out of this patient cohort, 23 (46%) patients had recurrent disease. The only significant factors that influenced risk of recurrence were original PET positive study (p<0.05) and patients with osteosarcoma (p<0.002). The type of surgical procedure, margins of original resection, race, age, gender, size, or the number of original nodules was not found to be significant.

CONCLUSION

Patients with osteosarcoma and PET positive disease at original presentation appear to be at the highest risk of recurrent pulmonary metastatic disease. New pulmonary lesions in these patients should undergo biopsy to confirm metastatic disease.

Surgical complications in pediatric surgical oncology

Rates of surgical complications in pediatric oncological patients increase with the extension of tumor surgery. Especially in advanced tumors this can mean a relevant challenge to surgeons: The balance between risk of complications and success of surgical treatment is often difficult to accomplish. As a consequence, surgeons not only need profound knowledge about resection techniques and surgical standard procedures but they also have to be able to control and manage surgical complications during and after surgery. This article highlights background and spectrum as well as management of selected surgical complications during or after surgery for abdominal pediatric solid tumors.